Now, i'm talking more prolonged sieges and less about direct castle assaults.
A few questions mainly:
So, how does a siege start?
I'm the lord of a keep, my scouts come rushing back telling me the Evil Lord X is 2 days march down the road. Not enough time to summon friendlies (who don't much like me anyway)
So i've got 2 days to make preparations, what do i do?
Who gets to stay inside the inner curtain wall? Just the people who already lived there? Blacksmishts/merchants/tradesmen etc? What about all the people outisde, would they just hope for mercy from the opposing lord?
Once the enemy arrives would there be a formal declaration of siege? Terms of surrender?
"Hey we'll hold out here for a while and if no one comes to help us out in 3 weeks i'll hand the castle over"
How would life in the attacking camp be? Many days of inaction and just guarding the road? Once every few days the defenders would fire off the occasional volley of arrows just to keep everyone on their toes?
Would there be the occasional exchanging of word/odd wartime comraderie between soldiers on the walls and those outside? Hey mate i'll throw up over a bag of apples if you toss down some fresh bread?
was the 'no one in or out' strictly adhered to or would there still be some forms of traffic?
You seem to imply you mean a medieval siege, but there have been many sieges after that as well.
One of the more "recent" sieges is that of Paris in 1870-1871. This was at the end of the Franco-Prussian war, which was disastrous to the French, to the point where the Prussian army had Paris surrounded and faced no real viable French threat from anywhere else in the country. The Prussians cut off contact between Paris and the rest of the world, bombarded them with their extremely long-range Krupp canons, and waited the capital out for four months before Paris capitulated and an armistice deal was signed.
This is a very simplified account, based on some of the questions you had about tactics and everyday life.
The Prussians first began shutting down rail lines in and out of the capital. As they got closer, it became more dangerous for people to move in and out of the city in carriages because many of them would be stopped and looted, or just not allowed to cross the Prussian army's lines. In some extreme cases, they would be taken as prisoners of war if the Prussians suspected them of carrying military orders or of acting as spies. Eventually, all the roads the came from the city had patrols, which meant the city was isolated from all contact with the rest of France.
Life during the siege of 1870-1871 was EXTREMELY boring. Despite most Parisians being in the military (there was a de facto draft of all able bodied residents), the majority of their duties were as watchmen on the ramparts around the city. Paris had not been a walled city in a century or more, so the ramparts were generally artificial hills and bunkers built on the outskirts of the city. This meant that there was a no-man's-land in between the defenders and the Prussians, which would sometimes "move" based on successful offensives on the part of both armies.
Being in the military during the siege meant that you had roll-call at some point in the morning, and then you may have a half-day of watch duties on the ramparts or - in the rare case there was an attempted armed push outside of the gates - you had to get ready for an offensive. The rest of the time, people drank (they drank A LOT), people waited in lines for a share of the dwindling food stores, or people read the newspaper. Around 90% of the nearly 80 Parisian newspapers kept publishing during the four month siege, despite limited paper supplies. There were even 28 new newspapers that appeared to satisfy the growing demand for daily stimulus! After a month of so, the theaters opened again, and you could finally go back to seeing plays. Unfortunately, the limited supply of gas meant that many of the theaters had to perform during the day to assure adequate lighting. Rationed gas supplies also meant a curfew at 10:30. The restaurants and cafes of Paris - which was sort of the "city that never sleeps" of the 19th century - had to close down at prime time!
It was basically impossible to leave once the siege began. Many people tried to, and only a few were not found by the Prussians and taken as prisoners or shot. The French government had to declare it illegal to leave the city, as if the threat of being shot wasn't enough.
The Prussians fired their canons infrequently (around one shot every four hours) in the first few weeks of siege, mostly at the ramparts around the city. There were very few military targets within the capital itself, and the risk of firing upon places like museums, theaters, or hospitals (which would have deeply angered other foreign powers) meant that the city was off-limits. The growing number of improvised medical centers to cater to the wounded also meant that some private residences could be considered off-limits to international war laws (the Geneva convention). The Prussians had to play it safe.
Eventually, in January of 1871 (the last month of the siege), the Prussians got bolder and fired into the city itself despite the fear of international diplomatic backlash. They mainly hit residences, but also a few schools, and they nearly took down a statue on the side of the not-yet-opened Opera Garnier. Civilian death estimates from Prussian canon fire are probably around 100. Civilian here meaning women and children.
By the time the Prussians were firing into the city, the food supplies were running dangerously low. People were eating rats and cats at this point. A rat, at the end of the siege, cost as much as three whole chickens did right before the city was blockaded. Bread was impossible to find, but if you did, it was probably made with whatever was on the floor of the bakery (this isn't an exaggeration). The Prussians' main offensive strategy was to wait for food supplies to force the French to capitulate, and that's exactly what happened.
The one comestible that never got close to running out was alcohol. As I mentioned earlier, Paris under siege drank much more than before. Since people didn't have much to do other than wait for news, sit on the ramparts, or read the newspaper, they got together in bars and talked about military strategy/politics and drank. There were many attempts on the part of the government to curb this behavior, which included increased military rounds and even the attempted removal of alcohol from "susceptible" (ie poorer) neighborhoods.
There's a really great rumor about the way Paris treated its high-ranking Prussian prisoners of war. Once they captured an officer, instead of throwing him in jail, they would take him out to the theater and bring him the best foods they had available. One newspaper even claims that they were able to find fresh asparagus to serve to a prisoner at a high-class restaurant on the boulevards. After this sumptuous meal (which may have also included oysters), they brought him to the theater to see a play by Moliere, on the very anniversary of Moliere's death - which meant the theaters was completely packed with enjoyment-deprived, drunk Parisians.
The idea was that the officer would eventually be traded for a French prisoner, and the Prussian would tell his commanders that Paris didn't at all seem like it was suffering because of the blockade; that it was still the fancy city of light it was a year ago. They even served asparagus in the middle of winter!
Even if these rumors were true, it still wasn't enough to convince the Prussians, and Paris eventually capitulated under very poor terms.
Main source:
Alistair Horne, "The Fall of Paris: The Siege and the Commune, 1870-1871" (Penguin, 2007).
hi! not that this is even begin to answer all your questions, but while you're waiting for responses to roll in, you may find some relevant info in this section of the FAQ